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Y=x^2-2x-5 vertex form

1 Answer

5 votes

Hey there! I'm happy to help!

First, we'll want to find the vertex of this parabola.

Given the equation y=ax^2+bx+c, the formula for the x-coordinate of the vertex is always
-(b)/(2a).

In our equation here, our a is 1 and our b is -2.


-(-2)/(2)=(2)/(2)=1

Now that we have our x-value of our vertex, we can plug it into our equation to find our y-coordinate.

y=1²-2(1)-5

y=1-2+5

y=-1+5

y=4

So, our vertex is at (1,4).

Vertex form is y=a(x-h)²+ k where (h,k) is our vertex. We know now that our vertex is (1,4) and we also know that our a is 1, so we can simply plug it in to this equation.

y=(x-1)²+4

Have a wonderful day and keep on learning! :D

User Swoox
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